by Staff Writer
Your new scanner can help you digitize your photo album, scan documents to send by e-mail and make copies for printing. Scanners and printers are essential office electronics for home or business. Knowing the answers to a few of these frequently asked questions will help you identify the right scanner for whatever imaging projects you have in mind.
What does scanner "color depth" mean?
Color depth, also called bit depth, is measured in bits; bits are individual data points (1 byte = 8 bits). Higher depth means greater contrast or differentiation in the image coloring. For text, a 24-bit scanner is adequate. For negatives, slides and transparencies, 30 or deeper is recommended. For photo scanners, 48-bit color depth is the way to go.
What factors affect the image quality of scans?
The image quality of your scans is mainly affected by the size of the scanner sensor and the method which your scanner uses to encode those images into digital image files.
Resolution: The resolution of an image is the number of pixels or dots that make up the picture, measured in pixels-per-inch (ppi) or dots-per-inch (dpi). A larger scanner sensor produces a higher resolution scan. Proper photo scanner resolution depends on how much you might enlarge or how detailed the final image must be. Document scanners produce readable scans at 300 ppi; 600 ppi is enough if the photo file won't be enlarged. Negative or slide scanners should operate at 1,200 ppi or above to ensure that they don't look blurry or pixilated when enlarged.
Interpolation: Scanners that advertise super high resolution, 4800 x 4800ppi or above, may use interpolation to add pixels between those scanned by the scanner sensor. The scanner averages the color of the surrounding pixels and calculates the color of pixels in between. In this way, a scanner can artificially enhance the clarity of an image. Different methods of interpolation and scaling have different effects on the final appearance of scanned text and photos.
Does my scanner require maintenance?
Yes. Dust and heat can cause damage to electronics and reduce the clarity of your scans. Unless your scanner is made for large-scale scanning, let it rest periodically when you're scanning lots of documents to prevent overheating.
Occasionally, use canned air to blow dust out of vents and openings. Keep the scanner lid closed when not in use.
Some scanner beds are made with treated glass, so only clean the glass on a flatbed scanner if your user manual recommends it.
Do printer scanners work as well as dedicated scanners?
It depends on the features. A printer scanner with a high dpi rating and a document feeder can work great for a small home office. Know which features you need in a scanner and check for printer scanners that match your preferences.